A number of fasteners have been used in the past for securing one object on another object, as for example, securing a first article such as for example a plastic sheet, which comprises a rib, on a second article, such as a metal or other rigid plastic sheet for example having a slot. However, the fasteners of this type, which are improved by the advances of the present invention, and which are being used presently, do not accommodate adequately cases in which the rib is longer than necessary, or the first article cannot approach the second article sufficiently, so that a considerable part of the rib remains outside the spring fastener, as it will be explained in detail hereinbelow.
Recently, a fastener has been disclosed in U.S. Pat. No. 6,718,599 B2, which is incorporated herein by reference, characterized by ergonomically balanced removal to insertion force ratio. However, even in this case, the Lever/Angle pulling force is relatively low.
Examples of other state in the art fasteners are disclosed in U.S. Pat. No. 6,718,599 (Dickinson et al.), U.S. Pat. No. 6,381,811 (Smith et al.), U.S. Pat. No. 6,353,981, U.S. Pat. No. 6,203,240 B1 (Hironaka et al.), U.S. Pat. No. 6,141,837 (Wisniewski), U.S. Pat. No. 6,074,150 (Shinozaki et al.), U.S. Pat. No. 5,987,714 (Smith); U.S. Pat. No. 5,919,019 (Fisher); U.S. Pat. No. 5,887,319 (Smith), U.S. Pat. No. 5,542,158 (Gronau et al.); U.S. Pat. No. 5,422,789 (Fisher et al.), U.S. Pat. No. 5,373,611 (Murata); U.S. Pat. No. 5,314,280 (Gagliardi), U.S. Pat. No. 5,129,768 (Hoyle et al.), U.S. Pat. No. 5,095,592 (Doerfling), U.S. Pat. No. 5,092,550 (Bettini), U.S. Pat. No. 4,981,310 (Belissaire), U.S. Pat. No. 4,712,341 (Harris, Jr. et al.), U.S. Pat. No. 4,701,984 (Wyckoff), U.S. Pat. No. 4,792,475 (Bien), U.S. Pat. No. 4,683,622 (Ohelke), U.S. Pat. No. 4,609,170 (Schnabl), U.S. Pat. No. 4,595,325 (Moran et al.), U.S. Pat. No. 4,431,355 (Junemann), U.S. Pat. No. 4,245,652 (Kelly et al.), U.S. Pat. No. 4,133,246 (Small), U.S. Pat. No. 3,864,789 (Leitner), U.S. Pat. No. 3,673,643 (Kindell), U.S. Pat. No. 3,525,129 (Holton), U.S. Pat. No. 2,825,948 (Parkin), U.S. Pat. No. 2,607,971 (Bedford, Jr.), U.S. Pat. No. 2,542,883 (Tinnerman), U.S. Pat. No. 2,424,757 (F. Klump, Jr.), U.S. Pat. No. 2,329,688 (Bedford, Jr.), and U.S. Pat. No. 2,322,656 (Murphy), among others.
None of the above disclosures of the present state in the art provide side spacers of any sort.